Rotary positive displacement machine for incompressible media

Abstract

In a positive displacement machine for incompressible media, with a working chamber (4) located in a stationary housing (1, 2) and having the configuration of a circular slot, a circular displacer body (8) located in said working chamber, is being held on a disk shaped rotor (3) driven eccentrically relative to the housing. The displacer body contacts the inner and outer circumferential walls of the working chamber at least one sealing line continuously progressing in operation, whereby the medium is conveyed from an inlet (6) to an outlet (7). The inlet is separated from the outlet by a land (5) extending radially in the working chamber (4). For the guidance of the displacer body relative to the housing an Oldham (cross keyed) coupling (9, 10) is provided, and for the circular drive of the displacer body a wobble rod (12, 12') is connected with a driving crank drive (13). In the area of the land (5) the inner and outer work spaces (27, 28) communicate with each other at the inlet ( 6) and the outlet (7). The displacer body (8) and the working chamber (4) have a circular configuration over the overwhelming part of their configuration. The ends on the inlet and the outlet sides of the displacer body and the working chamber, in an angular zone (α) of maximum 30°, have significantly smaller radii of curvature than that of the overwhelming circumference.

What is claimed is: 
     
       1. A positive displacement machine for incompressible media, comprising: a stationary housing;   a working chamber having inner and outer circumferential walls separated by a bottom surface, an inlet and an outlet, said working chamber being located in the stationary housing and having the configuration of a circular slot;   a land extending from said housing into the working chamber;   said inlet being separated from said outlet by said land;   a disk shaped rotor located within said housing and driven eccentrically relative to the housing;   a circular displacer body located in said working chamber and being held on said disk shaped rotor so as to be driven eccentrically relative to the housing in a manner such that in operation the circular displacer carries out a circular motion limited by the circumferential walls of the working chamber;   the curvature of said displacer is dimensioned relative to the curvature of the working chamber so that the displacer contacts the inner and outer circumferential walls of the working chamber at a sealing line continuously progressing in operation, thereby dividing the working chamber into inner and outer work spaces, by which work spaces the medium is conveyed from the inlet to the outlet;   said displacer body being interrupted in the area of said land;   a coupling is provided for interconnecting the displacer body relative to the housing;   a wobble rod connected to said displacer body and a driving crank connected to said wobble rod wherein said wobble rod as driven by said driving crank provides for the circular motion of the displacer body;   in the area of the land, the inner and outer work spaces communicate with each other at the inlet and the outlet;   the displacer body and the working chamber have an at least approximately circular configuration over the overwhelming part of their configuration;   the displacer body being arranged so as to seal over at least 360°;   wherein an end of said displacer body on an inlet side of the displacer body and the working chamber and an end of the displacer body on an outlet side of the displacer body and the working chamber, in an angular zone α of maximum 30°, each have significantly smaller radii of curvature than that of the overwhelming circumference.   
     
     
       2. The positive displacement machine according to claim 1, wherein the inlet and the outlet are located in the stationary housing directly at the land and open radially into the working chamber, and the bottom surface of the working chamber includes a recessed portion for allowing fluid communication between said inner and outer work spaces, said recessed portion being located in the area of the inlet and the outlet. 
     
     
       3. The positive displacement machine according to claim 1, wherein the inlet and the outlet are located directly at the land and open radially into the working chamber, and the frontal side of the displacer includes a recessed portion for allowing fluid communication between said inner and outer work spaces, said recessed portion being located in the area of said inlet under the displacer body. 
     
     
       4. The positive displacement machine according to claim 1, wherein: the wobble rod includes first, second, and third spherical sections;   the wobble rod is seated on its end on the side of the crank with the first spherical section in an articulation socket of the crank;   the wobble rod is supported at its other end with the second spherical section in a hemispherical articulation socket of the stationary housing, and   between the its two ends the third spherical section of the wobble rod is supported rotatingly and wobblingly in a hemispherical articulation socket in the hub of the displacer;   said positive displacement machine further comprising spring means insuring the full abutment of the spherical sections in the articulation sockets.   
     
     
       5. The positive displacement machine according to claim 4, wherein the second spherical section is set loosely on the wobble rod, and the spring means comprises a helical spring located between the second and third spherical sections. 
     
     
       6. The positive displacement machine according to claim 4, further comprising a sliding block in which is arranged the articulation socket provided to hold the third spherical section, said sliding block being displaceable under a spring load in the stationary housing. 
     
     
       7. The positive displacement machine according to claim 4, wherein the articulation socket arranged to hold the first spherical section is displaceable in a plane parallel to the axis of the crank drive. 
     
     
       8. The positive displacement machine according to claim 1, wherein the coupling comprises a freely moving intermediate ring, carrying on its flat sides two sets of lands arranged at 90° to each other for engaging corresponding grooves in the housing and rotor, with said lands being convex at friction surfaces and wherein the load bearing walls of the grooves are correspondingly concave to hold said lands, and that the bottom of the grooves is recessed to prevent contact with the land. 
     
     
       9. The positive displacement machine according to claim 8, wherein the friction surfaces of the lands and the load bearing surfaces of the grooves have a circular cross section. 
     
     
       10. The positive displacement machine according to claim 8, wherein in that the intermediate ring is an integral prestressed part together with the lands made of spring steel. 
     
     
       11. The positive displacement machine according to claim 1, wherein the land extends radially within said working chamber. 
     
     
       12. The positive displacement machine according to claim 1, wherein the coupling is an Oldham coupling. 
     
     
       13. The positive displacement machine according to claim 1, wherein the inlet and the outlet are located directly at the land and open radially into the working chamber, and the frontal side of the displacer includes a recessed portion for allowing fluid communication between said inner and outer work spaces, said recessed portion being located in the area of said outlet under the displacer body.